1. Field of Invention
The present invention relates to a nozzle for an LPI injector which can prevent the injection hole of an injector from being clogged with tar, by removing the gap between the lower end of the injector and the upper end of an icing tube.
2. Description of Related Art
LPI injectors are devices that inject liquid-state fuel pressurized by a fuel pump into a combustion chamber, in the fuel system of liquified petroleum gas (LPG) vehicles.
The LPI injectors are variously classified in accordance with valve operation, the type of control, and the type of injection, and particularly, are classified into a needle valve type, a pintle type including a pintle, and an orifice type including a ball valve and an orifice plate, in accordance with the shapes of nozzles. In particular, recently the orifice type having high injection efficiency is widely used.
As shown in FIG. 1, in the orifice type injector, an injector body 1 containing fuel is inserted and fixed in a housing 2. Further, a nozzle that injects the fuel at the lower portion of injector body 1 is composed of an icing tube 4 and an icing tip 3. Further, the portion connected with icing tube 4 at the lower portion of injector body 1 is composed of a ball valve 6, a valve seat 7, and an orifice plate 8.
According to orifice type LPI injector having the configuration described above, gaps B and A are defined between ball valve 6 and orifice plate 8 and between orifice plate 8 and icing tube 4, respectively.
The fuel remains in gaps A and B by evaporation of the LPG gas and the remaining fuel produces tar while repeatedly evaporating and liquefying. The tar adheres to an increasingly wide area as the time passes, such that it closes a hole 5 at the upper end of icing tube 4 which is the channel of the fuel.
That is, the tar-based foreign substances and pollutants contained in the LPG accumulate and interfere with injection of the fuel, and cause engine hesitation and have bad influence on the exhaust gas. Further, the accumulation of the foreign substances outside the injector spreads inside, such that a fuel leakage may be caused, and maintenance is difficult because ultrasonic cleansing is required to remove impurities.
As described above, the more the fuel pollutants, the more the foreign substances accumulating gaps A and B between the lower end of injector body 1 and the upper end of icing tube 4 increases and the fuel is not smoothly supplied to the combustion chamber of the engine. Accordingly, engine start becomes bad and the vehicle vibrates, and if excessive, the engine may stop in traveling.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.